CITY OF NEWBURGH – A Poughkeepsie developer is seeking approval from the City of Newburgh’s Planning Board to convert a former spring factory into a $2.7 million mixed-use complex combining a ground-floor restaurant with second-floor offices and third-floor apartments.On Tuesday, representatives for R.L. Baxter Corp. unveiled the company’s plan for creating seven top-floor apartments at the long-vacant 109 S.